This invention is directed to a system for forming a paper pallet. More specifically, it is directed to a system for forming a cardboard pallet having an improved configuration. This cardboard pallet is formed from cardboard panels which may or may not have been suitably treated or processed for increased rigidity.
Cardboard pallets are a necessity in the storage and transport of many industrial products. A single-decked pallet of the prior art generally includes at least three stringers which are parallel and spaced apart by a preset distance, a forklift member entry being provided between adjacent stringers. Such a pallet has a deckboard formed by a plurality of elongate wooden panels attached transversely across the top of the stringers. As lumber becomes increasingly scarce, there will be an increasing need for such wooden pallets to be replaced by pallets formed from other materials such as condensed cardboard panels. Cardboard panels, however, possess significantly less strength than wood panels. Consequently, prior art pallets formed from condensed cardboard panels generally suffer from several notable shortcomings.
Referring to FIGS. 1, 2, and 3, a prior art cardboard pallet 1 includes a deckboard 11 which is formed from a plurality of layered cardboard panels. Such a multi-layered deckboard 11 is supported by a number of cardboard stringers 12 attached to its underside. Manufacture of this prior art pallet 11 requires much time and skilled effort, as it invariably requires complex assembly steps practically suited only for manual assembly. For instance, a cardboard panel must be folded to form a stringer 12 before it is individually attached to the underside of the deckboard 11 by adhesive. Thus, the daily manufacturing yield of stringers 12, and consequently the manufacturing yield of pallets 1, is extremely low.
Another shortcoming of prior art pallets 1 resides in the fact that deckboard 11, being formed from layered cardboard panels, is characterized by relatively poor strength, bending quite easily when anything more than a nominal load is applied. This lack of strength results because the corrugations which provide reinforcement against forces applied parallel to the plane of each cardboard panel are not optimally oriented. The load applied on a pallet 1 generates primarily a downward force which is perpendicular to the direction along which the corrugations extend. The corrugations, therefore, are essentially of no consequence in reinforcing deckboard 11 against deformation due to such force, and where it has formed on its surface a fold line, the supporting strength of deckboard 11 is diminished even more. Stress concentration occurs along such a fold line, with pallet 1 eventually experiencing structural failure along that fold line if the load is not soon removed.
Some manufacturers add hardware maintenance or increase the layers of stringers 12 and deckboard 11 to enhance the strength of cardboard pallet 1, but the strength added thereby is limited. Moreover, when pallet 1 is lifted by a forklift, the entire load of that pallet 1 will fall directly on deckboard 11, causing it to bend. No amount of hardening agent and no practical number of additional layers will enable deckboard 11 to overcome the lack of strength inherent in its structural configuration. Hence, such a prior art cardboard pallet 1 is insufficient to replace wooden panels.